Biomedical subjects

Lars Friege

Publications and source records attributed to Lars Friege.

7 recordsLinked to original sources

PubMed2007

Effects of short- and long-term pulsed radiofrequency electromagnetic fields on night sleep and cognitive functions in healthy subjects.

There has been wide public discussion on whether the electromagnetic fields of mobile telephones and their base stations affect human sleep or cognitive functioning. As there is evidence for learning and memory-consolidating effects of sleep and particularly of REM sleep, disturbance of sleep by radiofrequency electromagnetic fields might also impair cognitive functions. Previously realized sleep studies yielded inconsistent results regarding short-term exposure. Moreover, data are lacking on the effect that short- and long-term exposure might have on sleep as well as on cognitive functions. Therefore, 10 healthy young male subjects were included and nocturnal sleep was recorded during eight consecutive nights. In the second, third, and last night, we investigated polysomnographic night sleep and cognitive functions. After the adaptation and baseline nights, the participants were exposed to a defined radiofrequency electromagnetic field during the following six nights. We analyzed polysomnographic night sleep according to Rechtschaffen and Kales [1968, Manual of Standardized Terminology, Techniques and Scoring System for Sleep of Human Subjects] as well as by power spectra and correlation dimension. Cognitive functions were investigated by an array of neuropsychological tests. Data analysis was done by comparing the baseline night with the first and last exposure night and the first two sleep cycles of the respective nights. We did not find significant effects, either on conventional sleep parameters or on power spectra and correlation dimension, nor were there any significant effects on cognitive functions. With our results, we are unable to reveal either short-term or cumulative long-term effects of radiofrequency electromagnetic fields on night sleep and cognitive functions in healthy young male subjects.

Adult↗

PubMed2005

Prevalence of gait disorders in hospitalized neurological patients.

The prevalence of gait disorders among neurological inpatients is unknown, although disturbed gait is a common symptom. Gait disorders often lead to loss of independence with restraints for the patients and caregivers and costs for the health system. We designed a prospective study and investigated all patients admitted to a neurological hospital during a 100-day period for the presence of a gait disorder. Clinical investigation and several disease-specific rating scales were carried out for 493 patients. In 60% of the patients, a disturbance of gait was diagnosed. Most frequent diagnoses were stroke (21%), Parkinson's disease (17%), and polyneuropathy (7%). Within these diagnoses, the rate of patients with disturbed gait was high in Parkinson's disease (93%), subcortical arteriosclerotic encephalopathy (85%), and motor neuron disease (83%). Advanced age, dementia, alcohol abuse, and treatment with antiepileptics, neuroleptics, benzodiazepines, and chemotherapeutics were identified as risk factors for a gait disorder. A decline of cognitive function was accompanied by a reduction of walking speed. According to these results, gait disorders are among the most frequent symptoms in neurology.

Adult↗

PubMed2005

Lung function in military oxygen divers: a longitudinal study.

It is increasingly recognized that professional diving may elicit adverse long-term effects on the lungs, but conflicting results have been reported from distinct diving cohorts. This study reports the longitudinal change in lung function in professional divers who employ closed-circuit oxygen rebreathing apparatuses. All oxygen divers who attended the German Naval Medical Institute between 1994 and 1999 for regular medicals underwent spirometry and were entered if they had at least two follow-up examinations. Forced expiratory flows and volumes at baseline and at maximum follow up were compared. There were 39 divers who presented at least 3 times during a median period of 5.8 (2.7-8) yr. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) amounted to 4.86 +/- 0.62 L and 5.89 +/- 0.67 L at baseline, and 4.83 +/- 0.64 L and 5.87 +/- 0.69 L at maximum follow up, respectively. The change over time was statistically not significant. Substantial exposure to elevated oxygen partial pressure while diving is not associated with an accelerated decline in lung function. Factors other than hyperoxia (e.g., venous gas microemboli and altered breathing gas characteristics) may account for the long-term effects that have been found in professional divers.

Adult↗

PubMed2004

Falls in frequent neurological diseases--prevalence, risk factors and aetiology.

The prevalence of falls among neurological patients is unknown, although disturbances of gait and posture are common. Falls may lead to burdens for the patient, the caregivers and the health system. We designed a prospective study and investigated all patients for a history of falls admitted to a neurological hospital during a 100-day period. Clinical investigation was carried out and several disease specific rating scales were applied. A total of 548 patients were investigated. Of all patients 34% had fallen once or more often during the last twelve months. A disturbance of gait was blamed for the fall in 55%, epileptic seizures in 12%, syncope in 10 % and stroke in 7%. Intrinsic risk factors for falls were high age, disturbed gait, poor balance and a fear of falling. As extrinsic factors we identified the treatment with antidepressants, neuroleptics and different cardiovascular medications, adverse environmental factors in the patients' home and the use of walking aids. Within the diagnoses, falls were most frequent in Parkinson's disease (62 %), syncope (57%) and polyneuropathy (48 %). According to these findings falls in neurological in-patients are twice as frequent as in an age-matched population living in the community. Falls in neurological patients are particularly linked to medication and disorders affecting gait and balance.

Accidental Falls↗

PubMed2003

Morning headaches in patients with sleep disorders: a systematic polysomnographic study.

OBJECTIVES: Patients with sleep disorders suffer more often from headache after awakening than healthy subjects. However, it still is a matter of controversy whether this applies only to patients with sleep apnea syndrome (SAS) or also to patients with other diagnoses of sleep disorders. METHODS: We asked all patients in our sleep laboratory about the frequency of past headaches and also ascertained the occurrence of morning headaches after awakening in the sleep laboratory. Polysomnographic recordings from nights before morning headache were compared with nights without following headache. Four hundred and thirty-two patients with sleep disorders (age range 18-86 years, 37% women) and 30 healthy subjects (age range 24-55 years, 27% women) participated in this prospective study. RESULTS: The reported frequency of past headaches and the frequency of morning headache in the sleep laboratory were significantly increased in patients with SAS and other sleep disorders compared with healthy subjects. The occurrence of morning headache in the sleep laboratory was associated polysomnographically with a decrease in total sleep time, sleep efficiency and amount of rapid eye movement sleep and with an increase in the wake-time during the preceding night. CONCLUSIONS: We conclude that morning headaches in patients with sleep disorders might be associated with particular disturbances of the preceding night's sleep. We speculate that dysregulation in anatomically identical central regions modulating sleep and nociception might be relevant to morning headache, rather than one particular sleep disorder such as SAS.

Adult↗

PubMedDate not supplied

Impairment of visuospatial memory is associated with decreased slow wave sleep in schizophrenia.

Cognitive impairments such as memory deficits and sleep disturbances are common clinical features of schizophrenia. Since sleep plays an important role in consolidation of memory, we hypothesize, that there is an interrelationship between distinct alterations in sleep and memory performance in schizophrenia. We studied 17 patients with schizophrenia on stable antipsychotic medication with amisulpride (age range 22-44 years; 7 women) and 17 healthy controls (matched for age, gender and educational level). Sleep was recorded and scored according to the standard criteria by Rechtschaffen and Kales. Immediately before polysomnography and the morning after we performed neuropsychological tasks including Rey-Osterrieth Complex Figure Test and a test for recall of spatial location for testing aspects of declarative memory and a mirror tracing skill for procedural memory. In comparison to healthy controls, the patients showed a significant increase in sleep onset latency and a significant decrease in sleep efficiency and amount of slow wave sleep (SWS). Furthermore, the patients' performance in recall of the Rey-figure and of spatial location the next morning was significantly impaired. These impairments in the tests for visuospatial memory were positively correlated with reduction in the amount of SWS and in sleep efficiency. These results point to a functional interrelationship between regulation of SWS and performance in visuospatial memory in schizophrenia. If these results of our pilot study hold true, they will allow the development of innovative treatment strategies for neuropsychological deficits in patients with schizophrenia.

Adult↗

PubMedDate not supplied

[In-patient treatment concept for acute crises of borderline patients on the basis of dialectical-behavioral therapy].

Whereas the Dialectical-Behavioral Therapy (DBT) by Marsha Linehan for chronic suicidal female patients with borderline personality disorder has also been successfully implemented for in-patient treatment, the management of recurrent crisis has continued to be a significant challenge especially for hospitals taking part in the mandatory health coverage. Therefore, we have established an acute, short-term crisis treatment concept for both genders on a locked unit which takes the different circumstances of acute crisis into account. It ought to be used under the conditions of acute psychiatry and at the same time meet psychotherapeutic demands of borderline treatment. The treatment basis is DBT. The treatment focus is to improve stress-tolerance, especially by skills-training, regarding the individual situation and problems at time of admittance. The in-patient treatment should not take more than three weeks. The short-time aim is a fast reintegration in ambulant treatment or motivation for a specific therapy as DBT, middle- and long-time aims are the improvement of the ability to cope with crises and to demand less in-patient care.

Behavior Therapy↗